Allah mentions here the valid excuses that permit one to stay away from fighting. He first mentions the excuses that remain with a person, the weakness in the body that disallows one from Jihad, such as blindness, limping, and so forth. He then mentions the excuses that are not permanent, such as an illness that would prevent one from fighting in the cause of Allah, or poverty that prevents preparing for Jihad. There is no sin in these cases if they remain behind, providing that when they remain behind, they do not spread malice or try to discourage Muslims from fighting, but all the while observing good behavior in this state, just as Allah said,
{No means (of complaint) can there be against the doers of good. And Allah is Oft-Forgiving, Most Merciful.}

Al-Awzai said, "The people went out for the Istisqa' (rain) prayer. Bilal bin Sa'd stood up, praised Allah and thanked Him then said, 'O those who are present! Do you concur that wrong has been done?' They said, 'Yes, by Allah!' He said, 'O Allah! We hear your statement,
{No means (of complaint) can there be against the doers of good.}

O Allah! We admit our errors, so forgive us and give us mercy and rain.' He then raised his hands and the people also raised their hands, and rain was sent down on them." Mujahid said about Allah's statement,
{Nor (is there blame) on those who came to you to be provided with mounts}

Mujahid said; "It was revealed about Bani Muqarrin from the tribe of Muzaynah."
Ibn Abi Hatim recorded that Al-Hasan said that the Messenger of Allah said.
"Some people have remained behind you in Al-Madinah; and you never spent anything, crossed a valley, or afflicted hardship on an enemy, but they were sharing the reward with you."
He then recited the Ayah,
{Nor (is there blame) on those who came to you to be provided with mounts, when you said: "I can find no mounts for you."}

This Hadith has a basis in the Two Sahihs from Anas, the Messenger of Allah said,
"Some people have remained behind in Al-Madinah and you never crossed a valley or marched forth, but they were with you."
They said, "While they are still at Al-Madinah?" He said,
"Yes, as they have been held back by a (legal) excuse."
Then, Allah criticized those who seek permission to remain behind, even though they are wealthy...